Facial palsy after cochlear implantation: incidence, etiology, and treatment outcomes: a systematic review and meta-analysis.

BACKGROUND

Facial nerve palsy (FNP) is a rare but potentially distressing complication following cochlear implantation (CI). While most cases are transient and reversible, the true incidence, etiological factors, and outcomes remain unclear due to heterogeneous reporting in the literature.

METHODS

We conducted a systematic review and meta-analysis following PRISMA 2020 guidelines. PubMed, EMBASE, Cochrane, and OVID databases were searched up to June 2025. Studies reporting FNP after CI were included. Incidence and recovery rates were synthesized using random-effects meta-analysis. Risk of bias was assessed using the Newcastle-Ottawa Scale. Data were managed with Zotero and analyses performed in Python.

RESULTS

Twenty-three studies were included, of which 17 were suitable for quantitative synthesis, encompassing 12,536 patients and 370 cases of postoperative FNP. The pooled incidence was 0.99% (95% CI 0.56-1.74%) under the random-effects model, with substantial heterogeneity (I² = 93.6%). Recovery was almost complete, approaching 100% in most studies, with only a few reporting slightly lower rates. The main etiological mechanisms were postoperative edema and viral reactivation (HSV/VZV). Most cases were successfully managed with corticosteroids, while combined corticosteroid-antiviral therapy accelerated recovery when initiated within 72 h. Only a minority required surgical intervention, including nerve decompression or device revision.

CONCLUSIONS

Facial nerve palsy following cochlear implantation is an uncommon complication and is reversible in the majority of cases. Although recovery rates are high, substantial heterogeneity exists in reported incidence and outcomes, reflecting variability in study design, reporting standards, and clinical management. Current evidence does not allow definitive conclusions regarding the comparative effectiveness of specific treatment strategies. Future prospective studies using standardized diagnostic criteria, outcome definitions, and reporting frameworks are needed to better clarify etiological mechanisms and optimize preventive and therapeutic approaches.